| 摘要 |
PURPOSE:To inhibit a rise in a water level and hence prevent overflow by throttling a hot water supply valve based on a specified flow rate when it is detected that the water level in a cistern remains continuously within a specified range for more than a fixed time. CONSTITUTION:When a water level detection means installed to a cistern 60 detects that the water level is in a predetermined zone C, a hot water supply mount valve 26 is throttled for 20 seconds so as to reduce the injection amount of hot water to the cistern 6 by 0.5l/min during that period. When the water level rises and reaches the zone D in spite of the above operation, the hot water supply amount valve 16 is throttled in continuous mode so as to reduce the injection amount to the cistern 60 by 0.5l/min. When the water level drops down to the zone B, the throttling of the hot water supply amount valve 26 is released so as to increase the flow rate. Since the injection amount of hot water to the cistern 60 is reduced in this manner, the difference between the injection amount and the supply amount is minimized so that the fluctuation in the water level may be slow, which makes it possible to control water level control easily and prevent the hot water from overflowing in the cistern. |
